I am fortunate enough to have a HiFi father that is a bit of a hoarder.
On a recent trip home for the 4th of July my father agreed to let me take ONE pair of his Technics SB-X50's home with me.
He purchased them new while he was on a trip to Japan in 1976.
They are rated at 93db sensitive and I would tend to agree with this rating based upon my initial low power tests.
They have a 1" soft dome, 3.5" paper mid with inverted neoprene surround and a 10" paper woofer with inverted cloth surround.
The surrounds on all of the drivers are still in very good shape.
The rubber parts even still have that bit of white powder that new rubber has on it.
The factory crossover points are 1000hz and 3000hz.
As is they really sound very good even for being 40 years old with dried up electrolytic caps.
They image VERY well and I can hear things all around the room from directly in front and out to the sides even slightly above and below.
The drivers are physically time aligned and the speakers were marketed as Linear Phase design.
I will be going through them and replacing the old electrolytic capacitors with Met-Poly except for the 330uF in the midrange tank (that will be a mix).
They are in near pristine condition and have a very slight grunge in the sound which is the reason I will be replacing the capacitors in the crossovers.

In this thread I will chronicle my progress and field any questions along the way.

No Way, this crossover looks very well thought out even compared to the modern designs and ideas.
I bet the engineers at Panasonic had their thinking caps on when they designed these.
Somewhere my father has all of the original documentation including impulse and phase response graphs.
From some of the scans I have seen on the internet of this documentation there would be NO WAY I could even come close to designing something comparable myself.

I have however already thought about changing the vinyl walnut veneer for real walnut veneer.

The crossover electric transfer would be similar to this, notice the inversion of phase on the tweeter (OP) working with horn loading.
In case someone wants to use other drivers, Visatons, SSs or others. Technics SB-X50 on thevintageknob.org

Anybody around Bozeman is welcome to stop by for a listen.
I will be picking up the bulk of my caps from ApexJR.
He is out of town for a few days so there will be a slight delay.
Tomorrow I will pull one of the woofers and get a look at the crossover.

Well, Inductor pointed to the VKnob site, and it says. "Thermal relays for each drivers are placed at the input point of the speaker coils set in as soon as excessive heat builds up caused by amplifier clipping ; the reset buttons are located at the back, just above the terminals."
I would skip those !